The Bathroom: Plumbing Products that Save Water and Energy

By now most architects know the impact of the Energy Policy Act legislation (EPAct) initiated in 1992 that mandated changes in common household equipment. According to this legislation all United States plumbing products must meet the following standards:

•	Toilets	1.6 gallons per flush (gpf)
•	Urinal	1.0 gpf
•	Faucets	2.2 gallons per minute (gpm)
•	Showerheads	2.5 gpm

To put this into perspective, pre-EPAct toilets flushed at 5 gpf, sending potable water into many already challenged community sewage systems. This was one of the many major factors in creating this new legislation. As the flushing mechanisms changed, so did the science of how the fixtures were designed. Manufacturers began to use computer modeling to design the china fixtures to optimize the hydraulic performance of the bowls. A new super-smooth material development in glazing using nanotechnology reduces mineral deposits on the toilet bowl, allowing for easier cleaning. New testing standards have been set by the American National Standards Institute, (ANSI) that were the result of solid waste tests using four different artificial pastes studying both drain line carry and flushing performance. No matter what type of toilet the design professional is choosing, a well-designed toilet will have been tested and will be WaterSense-labeled. This is one piece of equipment that is rarely replaced in a home and should not be hard to clean or difficult to flush properly. Durable, low maintenance, high quality and good performance are as important as appearance and when the professional specifies a Water Sense labeled toilet, there is a guarantee that this will mean third-party certification of the product.

HETs must use 20 percent less water than the current federal standard of 1.6 gpf, saving over 4,000 gallons of water per year. Photo: TOTO

Toilets: HETs, Dual-flush and Bidets

New high-efficient toilets or HETs must use 20 percent less water than the current federal standard of 1.6 gpf,saving over 4,000 gallons of water per year. All HETs are the WaterSense-labeled and as such meet the standards of a third-party testing agency. HETs can be single-flush or dual-flush but all HETs must meet the following criteria:

• Single-flush toilet must use 1.28 gpf or less;
• Dual-flush toilets must have a full flush no more than 1.6 gpf and a reduced flush no more than 1.1 gpf. Field studies indicate that in actual use such toilets will flush 1.28 gpf or less, on average.

When it comes to selecting environmentally friendly bathroom fixtures, dual-flush toilets are a popular choice. Users can select one button for the liquid flush and one for solid waste flush. Water use can be greatly reduced by choosing a dual-flush toilet that selectively provide a short or long flush depending on the use.

A common fixture in Europe, bidets are another type of toilet system becoming more popular in the U.S. as a choice for both water saving and ease of use for those with special needs. Today's most advanced bidets are toilet seats that have warm water sprays, heated seats and even built-in dryers. Seats can be added to almost any fixture and designers must include electrical outlets as part of the installation specification.

Faucets and showers

As an alternative to the bathtub, showers were popularized in the nineteenth century as means to consume less water, less space, less time, and require fewer repairs. After 1992, aerators or laminators were required to be added to restrict the flow of water and sometimes were placed on existing fixtures solely for the time of the building inspection, quickly removed by the owner in order to provide better water flow while washing and bathing.

The daily shower accounts for nearly 17 percent of residential water use or approximately 30 gallons per day. As of April 16, 2010, the EPA revised its new high efficiency showerhead specification to 2.0gpm in order to gain certification by its WaterSense labeling program. Exceeding even this new specification, some manufacturers have provided showerheads and hand-held showers that use no more than 1.75 gpm, a 30percent savings over the EPACT mandates. They have optimized shower system spray channel sizes and hydraulic efficiency to ensure shower power.

Controlling the flow of hot water contributes to the savings of both water and energy. Thermostatic mixing valves made with shape-memory alloys can respond to heat faster than older, wax-type valves. Nickel and titanium alloy coils expand and contract quickly to regulate water temperature more effectively. This shape-memory alloy technology removes the fear of scalding and drastic changes in water temperature from pressure drops from the use of other plumbing in the home. It also suppresses the water hammer at the end of a shower - the banging of plumbing pipes that results when water rushing through pipes is brought to a quick halt.